On Wed, Feb 3, 2010 at 2:12 AM, Emmanuel Charpentier <charp...@bacbuc.dyndns.org> wrote: > Le mercredi 03 février 2010 à 00:01 -0500, David Winsemius a écrit : >> On Feb 2, 2010, at 11:38 PM, Peng Yu wrote: >> >> > ?contrast in the contrast package gives me the following description. >> > However, I have no idea what Type II and III contrasts are. Could >> > somebody explain it to me? And what does 'type' mean here? >> > >> > *‘type’*: set ‘type="average"’ to average the individual contrasts >> > (e.g., to obtain a Type II or III contrast) >> >> In no particular order: >> http://courses.washington.edu/b570/handouts/type3ss.pdf >> http://core.ecu.edu/psyc/wuenschk/SAS/SS1234.doc >> http://n4.nabble.com/a-kinder-view-of-Type-III-SS-td847282.html >> >> Don't expect any follow-up questions to be answered or further >> citations offered. This is really more in the realm of statistics >> education than an R specific question. > > Nonwhistanding David Winsemius' closing remark, I'd like to add > something that should be requested reading (and maybe hinted at in > lm()'s help page) : > > http://www.stats.ox.ac.uk/pub/MASS3/Exegeses.pdf > > (BTW, despite is age, MASS *is* requested reading, and Bill Venables' > exegeses should be part of it).
Do you by any means indicate that MASS describes Type I, II, III, IV contrast? Although MASS describes contrasts, but I don't think it describes Type I, II, III, IV contrast. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.